package com.atguigu.gulimall.product.service.impl;

import org.springframework.stereotype.Service;

import java.util.*;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.Query;

import com.atguigu.gulimall.product.dao.CategoryDao;
import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> queryAllCatagory() {

        // 查到所有的分类
        List<CategoryEntity> entities = baseMapper.selectList(null);

        // 将查找后的分类进行组装
        List<CategoryEntity> level1Menus = entities.stream().filter(categoryEntities ->
                categoryEntities.getParentCid() == 0
        ).map((menu)->{
           // 通过map方法改变当前对象的值，再将筛选后的数据进行返回
           menu.setChildren(getChildren(menu,entities));
           return menu;
        }).sorted((menu1,menu2) ->{
            return  (menu1.getSort()==null?0:menu1.getSort()) - (menu2.getSort()==null?0:menu2.getSort());
        }).collect(Collectors.toList());
        return level1Menus;


    }

    /**
     * 删除传入节点的数据
     * @param ids
     */
    @Override
    public void removeCategoryByIds(List<Long> ids) {

        // TODO 1. 需要判断当前节点是否有引用
        baseMapper.deleteBatchIds(ids);

    }

    @Override
    public Long[] findCatelogPath(Long catelogId) {

        List<Long> pathIds = new ArrayList<>();
        List<Long> parentPath = findParentPath(pathIds, catelogId);

        Collections.reverse(parentPath);
        return parentPath.toArray(new Long[parentPath.size()]);
    }

    /**
     * 查出父节点id
     * @param pathIds
     * @param catelogId
     * @return
     */
    private List<Long> findParentPath(List<Long> pathIds, Long catelogId) {
        pathIds.add(catelogId);
        CategoryEntity parent = this.getById(catelogId);
        if (parent.getParentCid() != 0) {
            findParentPath(pathIds, parent.getParentCid());
        }
        return pathIds;
    }

    private List<CategoryEntity> getChildren(CategoryEntity root, List<CategoryEntity> all) {

        List<CategoryEntity> children = all.stream().filter(categoryEntity -> {
            return categoryEntity.getParentCid() == root.getCatId();
        }).map(categoryEntity -> {
            // 找到子菜单
            categoryEntity.setChildren(getChildren(categoryEntity, all));
            return categoryEntity;
        }).sorted((menu1, menu2) -> {
            // 排序
            return (menu1.getSort()==null?0:menu1.getSort()) - (menu2.getSort()==null?0:menu2.getSort());
        }).collect(Collectors.toList());

        return children;
    }

}